Field
Aspects of the present invention generally relate to a power transmitting apparatus, a power transmitting method, and a storage medium.
Description of the Related Art
Conventionally, there has been provided a technique for supplying electric power in a non-contact manner (a wireless manner). There are four types of non-contact power supply methods, that is, an electromagnetic induction method, a magnetic field resonance method, an electric field coupling method, and a radio wave receiving method. Among these methods, the magnetic field resonance method can transmit a sufficient amount of electric power over a long distance as its feature. With such characteristics, the magnetic field resonance method has particularly received attention among these four methods. In the magnetic field resonance method, a one-to-N power transmission method using the characteristic of long-distance power transmission has been discussed (see, e.g., Japanese Patent Application Laid-Open No. 2009-136132). The one-to-N power transmission method enables a power transmitting apparatus to wirelessly transmit electric power to a plurality of power receiving apparatuses.
The one-to-N power transmission includes a simultaneous power supply method and a time-division power supply method. In the simultaneous power supply method, the power transmitting apparatus simultaneously supplies electric power to the plurality of power receiving apparatuses, whereas in the time-division power supply method, the power transmitting apparatus sequentially supplies electric power to each of the power receiving apparatuses. The power receiving apparatus includes a power storage device such as a secondary battery mounted therein. The power receiving apparatus stores power in the power storage device using any of the simultaneous power supply method and the time-division power supply method. Among power storage devices, the secondary battery in particular needs to avoid being overcharged, over-discharged, and a rise in ambient temperature thereof. In such a non-contact power supply method, therefore, both of the power transmitting apparatus and the power receiving apparatus need to have functions of stopping power supply in case of abnormality.
The wireless power consortium (WPC) has developed a non-contact charging standard called “Qi”. With the “Qi” standard, a method for stopping the power supplied to a power receiving apparatus is discussed. According to this method, a power transmitting apparatus stops supplying the power in response to a request from the power receiving apparatus. Moreover, Japanese Patent Application Laid-Open No. 2012-44735 discusses a power supply stop method performed by a power receiving apparatus. According to this method, in a case where the power receiving apparatus detects any abnormality while electric power is being supplied, the power receiving apparatus stops the power supplied thereto. Japanese Patent Application Laid-Open No. 2012-44735 also discusses a method performed by a power transmitting apparatus which supplies power to a plurality of power receiving apparatuses using a time-division power supply method. In a case where one of the plurality of power receiving apparatuses stops the power supplied thereto, the power transmitting apparatus performs shift processing so that the power is supplied to another power receiving apparatus.
However, there are cases where the power transmitting apparatus is a cause of a power supply abnormality. In such a case, a similar abnormality may occur again if the power transmitting apparatus continues the power supply processing. The reoccurrence of the abnormality is not desirable.